Section 6: Super 2 Highways

Overview

A Super 2 highway is where a periodic passing lane is added
to a two-lane rural highway to allow passing of slower vehicles
and the dispersal of traffic platoons. The passing lane will alternate
from one direction of travel to the other within a section of roadway
allowing passing opportunities in both directions. A Super 2 project
can be introduced on an existing two-lane roadway where there is
a significant amount of slow moving traffic, limited sight distance
for passing, and/or the existing traffic volume has exceeded the
two-lane highway capacity, creating the need for vehicles to pass on
a more frequent basis.

Widening of the existing pavement can be symmetric about the
centerline or on one side of the roadway depending on right of way
(ROW) availability and ease of construction.

When evaluating the termination of a passing
lane at an intersection, consideration should be given to traffic
operations turning and weaving movements, and intersection geometrics.
If closure of the passing lane at the intersection would result
in significant operational lane weaving, then consideration should
be given to extending the passing lane beyond the intersection.

When switching the passing lane from one direction to another
(closing the passing lane in each direction), provide a taper length
from each direction based on L = WS, with a minimum 50 ft buffer
(stopping sight distance (SSD) desirable) between them. (Figure
4-2).